T. rex's killer reputation is true

Hollywood movies got it right. Tyrannosaurus rex hunted down and killed its prey, according to evidence that disproves long-debated theories that the dinosaur only scavenged from carcasses.

A discovery of a T. rex tooth lodged in the spine of a smaller plant-eating dinosaur provides "unambiguous evidence that the T. rex was an active predator," said a report published in Proceedings of the National Academy of Sciences. David Burnham, a lead researcher from the division of vertebrate paleontology at the University of Kansas calls the finding "the holy grail" of paleontology.

"It sends a chill down your spine, that T. rex was the monster in Jurassic Park that would hunt you down and kill you." Burnham said.

The 40-foot-long animal weighing about 7 tons has often been portrayed as the terrifying villain of dinosaur epics. Until the findings, however, there was no scientific proof. Some scientists have argued that T. rex was too slow to capture prey and had physical characteristics of a scavenger of dead animals rather than hunter of live prey.

"We have the bullet and the smoking gun," Burnham said. He says this discovery returns T. rex to the top of the Paleolithic food chain.

Bloomberg News

a new take on 'potty mouth'

The newest source of battery power for your cellphone is both cheap and abundant.

Scientists at the University of the West of England in Bristol report that microbial fuel cells using human urine can directly power a cellphone battery. The researchers first demonstrated in 2011 that our pee is viable fuel: As it cascades through a series of fuel cells, hungry bacteria consume it and release electrons, which generate an electrical current.

Their new research, published in the Royal Society of Chemistry journal Physical Chemistry Chemical Physics, presents two devices for converting human waste into talk time, which they hope will help people in remote areas stay connected. However, urine-powered conversations would have to be short and sweet. After 24 hours of charging, a Samsung phone stayed alive for 25 minutes — enough to send several texts and make a 6-minute, 20-second call.

sciencenow

evidence hobbits were distinct

So much about the extinct little people nicknamed hobbits remains roundly contentious 10 years after their fossils were discovered on the Indonesian island of Flores. But a new study has weighed in with strong support for the original hypothesis about them: that they were remnants of a previously unknown distinct species of the genus Homo that lived as recently as 17,000 years ago.

Detailed comparisons show that the single skull among the skeletal remains is "clearly distinct" from skulls of healthy modern humans, the study said. Thus the fossil specimen may well deserve its designation as a representative of an extinct species, which scientists have called Homo floresiensis.

The lead author, Karen L. Baab, an anthropologist at Stony Brook University on Long Island, said the findings in the journal PLoS One provided the most precise and comprehensive measurements to date of outer shape — every ridge and groove, every lump and bump — of the H. floresiensis cranium. The researchers, who included Kieran P. McNulty of the University of Minnesota, concluded that the H. floresiensis cranium was more similar to the extinct fossil hominins than to normal modern humans or those with pathologies.

Loss of water from rocks during drought caused California's Sierra Nevada to rise nearly an inch (2.5 centimeters) in height from October 2011 to October 2015, according to a new NASA study made public Wednesday.

A federal judge says state criminal court judges in New Orleans have a conflict of interest because they rely on fines and fees for court funding — raising legitimate concerns over whether the court's financial needs might affect decisions on whether low-income defendants are able to pay.